Meet 5 of the world's wealthiest and most eligible bachelorettes

Elizabeth Holmes, the wealthiest self-made woman in the world, is single.Kimberly White/Getty Stringer

You could call them the most eligible bachelorettes in the world.

Five of the wealthiest women on earth are still unmarried, according to Wealth-X, a company that conducts research on the super-wealthy. With Valentine's Day in mind, it provided us with a list of the richest bachelorettes in five age groups: 20s, 30s, 40s, 50s, and 60s. Combined, they're worth $46 billion.

Meet five of the wealthiest in the world below, including owners of a biotech startup and a luxury-clothing business.

20s: India Rose James

India Rose James inherited an estimated 40% of her maternal grandfather Paul Raymond's $1 billion empire upon his death in 2008. His wealth — known as the Soho Estates —came from varied property investments in London's Soho district, establishing Britain's first adult-entertainment bar, and introducing pornography magazines to the country through Paul Raymond Publications.

James is currently focused on Soho Revue Gallery, the young artist-focused contemporary-art gallery she opened last spring with her then boyfriend Will Pelham. The socialite has breakfast at the family-owned Soho House every morning, enjoys traveling, and aspires to follow in her grandfather's footsteps to become "an entertainer."

30s: Elizabeth Holmes

Elizabeth Holmes is the youngest female billionaire in the world thanks to the success of her pain- and needle-free blood-testing company Theranos. When she was 19, Holmes dropped out of Stanford to found the company and has dedicated her life to it. According to a 2014 New Yorker profile, the CEO lives in a "two-bedroom condo in Palo Alto...no longer devotes time to novels or friends, doesn't date, doesn't own a television, and hasn't taken a vacation in ten years."

Though Holmes' image is that of a well-intentioned hard worker, she's facing harsh criticism for reports claiming dodgy business practices. "This is what happens when you work to change things," Holmes fired back. "First they think you're crazy, then they fight you, then you change the world."

Despite being one of the most affluent women in Turkey, Sahenk isn't a public fixture. She's a behind-the-scenes advocate for women's leadership and development and an active philanthropist as president of the Ayhan Sahenk Foundation, which supports education, the environment, and social and healthcare-related causes. She also reportedly has a passion for collecting antique Turkish art.

50s: Shari Arison

Israeli-American Shari Arison is the owner of Arison Group, a global investment and philanthropy company founded by her father. Ithas major interests in finance, real estate, infrastructure, renewable energy, and water. When Arison's father died in 1999, she inherited about 35% of his wealth.

The businesswoman and philanthropist authored four books on the subjects of good deeds and sustainability and is a major advocate of community service. The thrice-divorced mother of four has residences in Tel Aviv, Israel, and Bal Harbour, Florida.

60s: Alice Walton

Though she's one of four heirs to the Walmart fortune — and the 15th richest person on earth — Alice Walton never took an active role in the mega-retailer's daily operations. Instead, she's become a patron of the arts with a personal collection that includes pieces from Andy Warhol, Norman Rockwell, and Georgia O'Keeffe. In 2011, the heiress opened the Crystal Bridges Museum in Arkansas, where a number of her famous paintings are on display.

Walton is active in her family's philanthropic endeavors and recently donated 3.7 million of her Walmart shares — worth about $225 million at the time — to the Walton Family Foundation. The divorced billionaire's personal real-estate portfolio includes a 6,346-square-foot New York City condo and a recently listed pair of $48 million Texas ranch properties, where she raised and rode horses.